Tweezers



June 24, 1930. L GLAS 1,767,175

TWEEZERS Filed Sept. 26, 1929 INVENTOR Patented June 24, 1930 ISIDORE B. GLASS, WATEBZB'U'BY, CONNECTICUT TWEEZEBB Application filed September 2e,' 1a29. Serial No. 895,362.

This invention relates to tweezers, and

more particularly to an improved form of watchmakers tweezers for facilitating the adjustment of the curvature of new or injured hair-springs, and for other purposes.

One object of this invention is to provide tweezers of the above nature comprising a pair of cooperating normally-open spring arms, one of which is provided with a rounded convex interior rib and the other of which has a concave groove for fitting about said rib.

A further object is to provide tweezers of the above nature, which will be simple in construction, inexpensive to manufacture,

easy to manipulate, compact, and very efficient and durable in use.

With these and other objects in view there has been illustrated on the accompanying drawing one form in which the invention may be conveniently embodied in ractice.

Fig. 1 represents a perspective view of the tweezers shown in open position.

Fig. 2 is a side view on an enlarged scale of the aws of the tweezers which are shown in closed position.

Fig. 3 is a sectional view of the tweezers,

taken along the line 33 of Fig. 1.

Fig. 4 is a fragmentary view of a watch movement showing in section the appearance of the tweezers when in operating position for correcting the curvature of the outer turn of the hair spring.

It has been the practice among watchmakers when adjusting the incorrect curvature of a hair-spring, to employ tweezers having flat surfaces on the inside of its aws. With such flat-jaw tweezers it was quite difiicult to correct the shape of the hair-spring coil since the wire of said coil could be bent only at a single point along its length. Consequently, to produce a smooth job, 'It was necessary to give the wire several successive bendings or else to employ two pairs of tweezers holding one in each hand. Moreover, owing to'the relatively large points of the old form of tweezers, it was impossible to readjust the curvature of the inner closelywound turns of the wire coil without remov- 50 ing said coil entirely from the watch or from the bridge; (3) removal of the hairclock movement. In many cases this operation of removing the coil was uite troublesome and time-consuming, an other turns of the coil besides the one being corrected were quite apt'to be bent out of adjustment during the removal operation.

By means of the present invention the above and other disadvantages have been avoided, and an improved form of tweezers has been provided by means of which the in- 6 correct curvature of a hair-spring may be readily corrected without removing it from the watch or clock movement. Moreover, the operation of correcting the curvature of a hair-spring coil may be accomplished on the average in about one-half the time required with the old form of tweezers. Again, it has been found that when using the present form of tweezers, the number of replacements owing to injury of hair-coil sprin s during the repairing thereof is very great y reduced and consequently danger of damaging other parts of the movement while removing and replacing the spring is entirely avoided.

The following steps in the repair operation are thus eliminated:

(1) The removal of the bridge from the movement; (2) removal of thehair-spring spring from the balance wheel staff for correcting the curvature; (4) replacement of the hair-spring on the balance wheel staff; (5) replacement of the hair-spring on the bridge; and (6) replacement of the bridge in the movement.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numerals 10 and 11 indicate respectively a pair of jaws, which are bowed outwardly slightly at 12 and 13 to form convex outer surfaces to facilitate the manipulation of the tweezers by the hand of the watchmaker. The rear ends of said jaws 10 and 11 are connected rigidly together, as by welding to a small insert plug 14 located therebetween,v as clearly shown in Fig. 1.

The jaws 10 and 11 are provided with finely pointed ends 15 and 16. The inside 100 surface of the jaw 10 is rovided with a ta groove extending di erent distances from the point.

pering oove 15', sai

'rearwar ly from the point/15 and gradually widening and flattening until it joins the flat surface of the jaw at 17. The front end 'of the jaw 11 is rovided with a rounded inner rib 18 adapte to fit snugly in the-groove 15" of which it is substantially a 'counte art when the two ether. In Fig. 4, the useof the invention for adjusting an incorrect curvature of the outer turn 19 of a hair-spring 20 is illustrated, the

numeral 21 representm the usual watch movement, having a bri go 22, a staff 23, a regulator arm 24, a coil-engaging eye 25, and a balance wheel 26.

Operation In operation, assuming that the outer turn jaws are forcibly presse toopposed surfaces of differing curvatures at In 'testimon signature to t 's 19 of the hair-spring 20 has been injured,

the extremities 15 and 16 of the jaws 10 and 11 will be inserted in the movement, as

shown in Fig. 4, in position to embrace'the sides of said outer turn 19. The operator will then press the -aws 10 and 11 toward each other with s inner turnsof the hair-s ring has been in-.

ient force to produce the correct curvature desired. If one of the jured, the operation is slmilarto that just described, and may be performed without removal of the hair-spring from-the movement 21.

One advantage of the present invention is that by the use of the-cooperating curved surfaces of the ribbed and grooved jaws of the tweezers, 'it is possible to vary the amount of bending produced in the wire spring quite accurately. This is due to the tapering of the groove and rib so that different curvatures may be imparted by gripping the spring at different distances from the points-the reduced point giving the smallest curve desired.

While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure but may be modified and embodied in vawhat is claimed as new, and for which it is desired tosecure Letters Patent, is:

In a watchmakers tweezers, a pair of I jaws connected together at their rear ends, the forward ends of said jaws being pointed,

one of said pointed ends havin an interior rib and the other poihted en having an interior groove for fitting. said rib, said groove. and rib tapering so as to provide whereof, I have aflixed my ecification.

SIDORE B. GLASS. 

